Vista Laptop to XP desktop internet connectio

Hello,
I'm trying to connect my Windows XP Student Edition desktop PC to my Windows Vista Home Premium wireless internet connection. I have a cross-over and I'm able to set up file sharing with ease but cannot access internet connection from my laptop to PC. I put them both in the same workgroup (they share files even if they're in separate workgroups) and have enabled the internet sharing from the laptop. I'm able to connect to both my wireless hub and my LAN but unable to get internet connection and it says IPv6 is limited on both computers. I cannot LAN games through IP (like Diablo II) either. I don't understand why I can share files yet not access internet or LAN games. Any help is much appreciated!!!